Saw a trick for stubborn injector lines at a shop in Boise

I was at a heavy equipment yard in Boise yesterday, and one of their lead techs was fighting a seized high-pressure line on a Duramax. He grabbed a small butane torch, not to heat the nut, but to warm the whole line fitting for about 30 seconds. Then he hit the nut with a shot of penetrating oil. He said the quick heat makes the oil wick in way faster. It popped loose on the first try with a line wrench. Anyone else use this heat-then-oil method on stuck fuel fittings?

3 comments

3 Comments

cameronb5219d ago

My first time trying that trick was on a frozen brake line fitting. I used way too much heat like an idiot. Melted the rubber hose right next to it. @phoenix_wells has the right idea with a quick warm up. Just a little heat makes a huge difference. It pulls the oil right into the threads. Now I do it on everything from fuel lines to hydraulic fittings. Saves my knuckles.

phoenix_wells1mo ago

My old foreman taught me to always oil first, then heat. I argued with him about it for years. Seeing that exact trick on a Cat 3406 last winter made me a believer. The quick heat opens up the threads just enough to let the oil get deep fast. Now I keep a little butane torch in my box just for that job. It saves so much time on crusty diesel fittings.

jordan6471mo ago

That Cat 3406 is a perfect example. @phoenix_wells, I'm curious about the oil choice. On a really seized fuel line fitting, would you still reach for standard penetrating oil first, or do you go straight for something like a 50/50 mix of acetone and transmission fluid? I've seen guys swear by the homemade mix, but I wonder if the heat changes which one works best.